RTLS and Ranging

Wireless Connectivity Ultra-Wideband
1

Hi Staff,
We want to design a system for:

  1. Collision avoidance inter-tag communications . Tags in the field must communicate with others and, by a previous filter (e.g. RSSI), the must check the collision distance with each other in the network.

  2. Our Tags in the field must send RTLS packets every 20-30 seconds in order to get their position in the fields.

  3. We want to reduce the number of anchors installations thats why we opted for your Fira QM35825dk-05 since we see its a AoA + TWR complete solution.

Regarding the TAG side:

  1. we need to send collision packets every 100-200 msec . Do you think there is a limitation ?

We already have our MCU and for the first step we can interface it with your DWM3000 by SPI or similar to send both type pf packets (collision and RTLS). Do you think dwm3000 is a good solution ?

  1. in the third step we can replace our MCU+DWM3000 with your complete solution (nordic based)

  2. RTLS packets and collision packets must be customized as per our need

Regarding the Anchor:

  1. we have our linux anchor to interface with your QM35825dk-05 .

2. Is your QM35825dk-05 kit schematic available in order to redesign it by our engineering?

  1. Is the kit firmware available for some customization if we need it ?

Thanks a lot

2

From your post, it sounds like you’re aiming to support both periodic RTLS positioning and more frequent tag-to-tag communication for collision avoidance on the same UWB device.

Using a DWM3000 with your own MCU over SPI is a reasonable approach, and transmitting every 100–200 ms is not an inherent limitation of the device. The main considerations will be overall system architecture and scheduling, particularly as the number of tags and communication demands increase.

Regarding your QM35 questions: access to the schematic requires an NDA, so you would need to reach out to your sales contact to obtain it: How to buy,support & guidance - Qorvo The firmware is publicly available, but it is provided as a black box and cannot be modified: QORVO_SDK / Public / DevKits / qm35-sdk · GitLab

3

Hi Akash,
thanks for reply.

Regarding the RTLS : our approach is to use AoA +TWR by implementing an QM35 anchor (the same of the kit) with 3-4 antenna . So every 20-30 sec:

  1. the tag will send rtls packet
  2. the qm35 will receive and calculate the AoA
  3. the qm35 will make a pairing session with the TAG very quick to calculate the TWR double side distance.

In this way I will not need triangolation by using more anchors.
Do you think this is possible?

Regarding collision avoidance:

  1. for now we will use the external DWM3000
  2. for the future we can use the Fira protocol by replacing our MCU with your SOC so that we should have 8 inter-tag communications already in the fira stack. Can you confirm this, in that case can we stay at 100msec, or we need to do custom firmware in anyway ?
4

Hi Akash,
can you supportplease?
in addition , we have Raspberry 5 (ubuntu desktop) and we want to connect QM35825DK-05 via USB
. Are they compatible ?
Thanks a lot.
Nicola